BigWiz,
Hey and welcome! I am a fellow new person and thought I might throw in a couple of pennies. Keep in mind I am not trying to get in between what is a very friendly and cordial debate about sand, etc.
Based on what I have researched, here are some points about aragonite. It is actually composed of a substance close to the skeletons of coral, or exactly (depending on who you read). This substance (calcium carbonate, I think) helps to stabilize the ph in your tank by dissolving when things get too acidic and restoring the ph balance (so your fish will not cry "I'm melting!" JK LOL).
As far as the Bare Bottom (no sand or 1" or less of sand) versus the Deep Sand Bed (4"+ of sand) there are a LOT of opinions. I am not convinced, based on a lot of reading, that either is completely correct and you should read up on it yourself. Just do a search on the two topics and you will find lots of stuff. People get very into this topic.
As far as live rock I think more people will lean towards having it than not having it. I personally never really thought about it, I like the way it looks.
HTH!
E